The present invention relates to a keyboard water-resistant structure, in particular, to a water-resistant structure for keyboard assemblies with enhanced water-resistant ability.
FIG. 1 is an exploded perspective view showing the structure of a keyboard assembly 1. The keyboard assembly 1 comprises a keyboard hood 11, a plurality of key caps 19, an elastic water-resistant sheet 15, a circuit membrane 14, a metal plate 13, and a keyboard base 12. The water-resistant sheet 15 is made of rubber, and an endless flange 151 is integrally formed on its peripheral rim. Furthermore, plural elastic protrusions 155 are formed on the elastic water-resistant sheet 15, and plural through holes 157 are formed in the elastic water-resistant sheet 15.
FIG. 2 is a cross-sectional view showing the internal structure of the fabricated keyboard assembly 1 shown in FIG. 1. The metal plate 13 is affixed on the keyboard hood 11 by means of bolts 17 and the keyboard base 12 is affixed on the keyboard hood 11 with the aid of bolts 18. The water-resistant sheet 15 and the circuit membrane 14 are disposed therebetween. FIGS. 3A, 3B and FIG. 4 are enlarged cross-sectional views respectively showing the portions Z1, Z2, and Z3 in FIG. 2.
As shown in FIGS. 3A and 3B, a downward-extending flange 111 is integrally formed with the keyboard hood 11. The metal plate 13 strongly urges the water-resistant sheet 15 toward the flange 111 while the keyboard base 12 is brought to connect with the keyboard hood 11 by means of the bolts 18. Compared with the water-resistant sheet 15, the downward-extending flange 111 is rigid. Therefore, deformation of the water-resistant sheet 15, which is induced by tight contact between the downward-extending flange 111 and the water-resistant sheet 15, primarily takes place circular flange 153 side. Due to that fastening force is normal to the water-resistant sheet 15; it will cause irregular wrapping of the water-resistant sheet 15 at the portion near the downward-extending flange 111. For that reason, there exists a possibility that water enters the keyboard assembly from the gaps caused by irregular wrapping of the water-resistant sheet 15. Accordingly, the water-resistant sheet 15 will not function as a water-resistant member any more, and it is unable to prevent water from entering the keyboard assembly.
As shown in FIG. 4, a downward-extending flange 112 with a deep hole 115 formed therein is integrally formed with the keyboard 11. A circular flange 153 facing the downward-extending flange 112 is formed on the water-resistant sheet 15. When the keyboard 11 and the keyboard base 12 are fastened together, the downward-extending flange 112 is brought to strongly urge the circular flange 153 that is upheld by the metal plate 13. As described above, the bolts 17 are used for fastening the metal plate 13 with the keyboard hood 11. The fastening forces exerted by the bolts 17 are always normal to the water-resistant sheet 15. Compared with the circular flange 153, the downward-extending flange 112 is rigid. Therefore, deformation induced by tight contact between them will primarily take place on the circular flange 153 side. Therefore, the fastening force exerted by the bolts 17, which is normal to the water-resistant sheet 15, will cause irregular wrapping of the water-resistant sheet 15 at the portion surrounding the bolts 17. For that reason, it is possible that water enters the keyboard assembly from the gaps caused by the irregular wrapping of the water-resistant sheet 15.
Furthermore, as shown in FIGS. 3A and 3B, it is essential to keep a tight contact between the endless flange 151 and the downward-extending flange 111 so as to prevent water from entering the keyboard assembly. Therefore, a high accuracy in their dimension is required. The same situation happens in the portion of the keyboard assembly shown in FIG. 4.
It is therefore an object of this invention to provide a keyboard assembly with a water-resistant structure that can strongly prevent water from entering the keyboard assembly.
The keyboard assembly according to this invention is used for inputting data into a computer via keys. The keyboard assembly has a keyboard hood, on which keys are disposed; a circuit membrane disposed within the keyboard assembly, for being actuated by the keys disposed on the keyboard hood; an elastic water-resistant sheet disposed between the keys and the circuit membrane; and a keyboard base fastened to the keyboard hood so as to enclose the water-resistant sheet and the circuit membrane therebetween. The keyboard assembly is characterized in that: the keyboard hood is provided with a plurality of first slant wall extending toward the keyboard base; the keyboard base is provided with a plurality of second slant wall extending toward the keyboard hood and in parallel with the first slant wall; and the elastic water-resistant sheet is provided with upward-extending slant verges sandwiched between the first and the second slant wall so as to form a water-resistant structure when the keyboard assembly has been fabricated.
Furthermore, the keyboard assembly is characterized in that: the keyboard base is fastened to the keyboard hood by fastening screws passing through the through holes formed in the centers of the bosses of the keyboard base; the fastening screws are screwed into holes formed in protrusion portions 219 formed together with the keyboard hood; and step-shaped portions are formed on the tip ends of the protrusion portions 219 so as to form tight water-proof seal between the keyboard hood and the base when the keyboard assembly has been fabricated.
Furthermore, the keyboard assembly is characterized in that: plural pairs of first parallel ribs are formed on the base; the elastic water-resistant sheet is in a shape that it can be deeply embedded into the first slots formed between each pair of the first ribs and can cover the ribs and the keyboard base when the keyboard assembly has been fabricated; and a plurality of second ribs are formed on the keyboard hood, which are deeply embedded into the second slots of the water-resistant sheet when the keyboard assembly has been fabricated.
Furthermore, the keyboard assembly is characterized in that: plural pairs of third ribs are formed on the keyboard hood; a plurality of fourth ribs are formed on the water-resistant sheet; the fourth ribs are in a shape that they can be deeply embedded into the slot formed in each pair of third ribs when the keyboard assembly has been fabricated.